Dioecy seems to be most common in tropical areas and in stressful or
depauperate
habitats. The flowers are most likely to be pollinated by insects. There is
a paper
published in Biotropica, September 2000, "Variation in Gender and
Flower-Size
Dimorphism in the Dioecious Tree Dombeya ciliata, an Endemic to La Reunion
Island".
The paper also provides a good list of references .
Regards, Jeff
http://www.tropicaldesigns.com
""Janice M. Glime"" <jmglime at mtu.edu> wrote in message
news:Pine.GSO.4.21.0011091950490.26255-100000 at login.ice.mtu.edu...
> Sex determination in plants can also depend on available nutrients, and
> may be the case in some plants that appear to be dioecious. This is the
> case with Jack-in-the-pulpit (Arisaema triphyllum). It is first sterile,
> then in 2-3 years it is male, then the following year if enough energy is
> available, it becomes female; then the cycle starts over.
>> The first sex chromosomes were found in the moss Mnium. I don't know
> which species, so I don't know if it was dioecious.
>> Janice
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> Janice M. Glime, Professor
> Department of Biological Sciences
> Michigan Technological University
> Houghton, MI 49931-1295
>jmglime at mtu.edu> 906-487-2546
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